1. Field of the Invention
In general, the present invention relates to a sorting machine and, more particularly, to a sorting machine, which feeds a sorted item into a carrier box, delivers the sorted item, and discharges the sorted item from the carrier box at a predetermined location according to the sorted item.
2. Description of the Related Prior Art
Heretofore, various sorting machines have been put to practical use, which automatically sort according to a different destination a thin paper category such as post cards, letters, periodicals, catalogues, books and the like or a flat mail item such as CD, video cassettes and the like (hereinafter, referred to as a lightweight mail item), which are delivered by mail or courier service.
Among the above-described sorting machines, there are some sorting machines, which perform the sorting in such a manner as to feed the lightweight mail item into the carrier box, deliver it, open the bottom lid of the carrier box at a predetermined location according to each lightweight mail item, and allow the lightweight mail item to be dropped into a sorting port.
Now, a conventional sorting machine will be described below with reference to the drawings.
FIG. 1 is a schematic top view for explaining the entire structure of the conventional sorting machine, and FIG. 2 shows a front view thereof.
Further, FIG. 3 is a view for explaining the sectional structure of essential portions of the conventional sorting machine, and shows a schematically enlarged sectional view taken on line M—M of FIG. 1.
Referring to FIGS. 1 and 2, a sorting machine 100 comprises a sorting machine main body 110 for sorting the lightweight mail item and a feeder 120 for feeding the lightweight mail item into the sorting machine main body 110.
The sorting machine main body 110 is a slender machine of an upper and lower two level structure, and comprises a chain conveyer 130 along a double endless loop route. The sorting machine main body 110 comprises an IN side turn back portion 111, a transfer portion 112, an intermediate turn back portion 113, a sorting portion 114, and an OUT side turn back portion 115 in this order from the IN side.
When seen from above, a chain conveyer 130 has two almost oval chain conveyers, which are different in the length of a longitudinal direction, and are connected mutually at the OUT side turn back portion 115.
Specifically, this double endless loop route comprises a line P provided in the near side intermediate level of the sorting machine main body 110, a line P-Q inside of the IN side turn back portion 111, a line Q provided in the innermost side upper level coupled with the line P by the line P-Q, a line Q-R inside of the OUT side turn back portion 115, a line R provided in the near side upper level coupled with the line Q by the line Q-R, a line R-S inside of the intermediate turn back portion 113, a line S provided in the innermost side intermediate level coupled with the line R by the line R-S, and a line S-P inside of the OUT side turn back portion 115 which connects the line S and the line P.
Referring now to FIG. 1, between the sorting portion 114 and the OUT side turn back portion 115, the line Q, the line Q-R, and the line R are shown by a solid line, and the line P, the line S, and the line S-P are shown by a chain line. Although the solid line and the chain line substantially lie one-upon-another, they are illustrated in such a manner as to be shifted from one another for better understanding.
As shown in FIG. 3, a plurality of carrier boxes 131 hangs from the chain conveyer 130. The chain conveyer 130 delivers these carrier boxes 131.
This carrier box 131 is a carrier box capable of housing and delivering the lightweight mail item. The carrier box 131 has an opening portion at an outer peripheral side surface for throwing the lightweight mail item, and has a bottom lid 139 at the bottom for allowing the lightweight mail item to be dropped at a predetermined location. Moreover, the carrier box 131 is provided with bottom lid opening and closing means (not shown).
Further, the carrier box 131 is provided with a plurality of compartments in the advancing direction so that the lightweight mail items can be effectively delivered. In such a case, the bottom lid opening and closing means is provided for each compartment.
The transfer portion 112 is coupled with a feeder 120 comprising a transfer belt 121. In this feeder 120, the transfer belt 121 transfers the lightweight mail item to the transfer portion 112 one by one. The transfer portion 112 throws the lightweight mail item transferred by the transfer belt 121 into the carrier box 131. For example, when a plurality of sorting compartments is formed in the carrier box 131, one lightweight mail item is thrown into one sorting compartment.
In general, the transfer potion 112 is coupled with a plurality of feeders 120 according to the processing speed of the feeder 120.
The sorting portion 114 has gathering boxes 132 juxtaposed below the carrier box 131 of each line.
A controller (not shown) of the sorting machine 100 opens the bottom lid 139 of the carrier box 131, which delivers the lightweight mail item, by using the bottom lid opening and closing means at a predetermined location according to each lightweight mail item. The lightweight mail item drops into the gathering box 132 into which it is to be sorted. The sorting machine 100 sorts the lightweight mail item in such a way.
Incidentally, the gathering box 132 is a rectangular box-shaped container. Hence, the port of the direct gathering box 132 becomes a sorting port for sorting the lightweight mail item, which is dropped from the above portion.